The actor -- also known for his role opposite James Franco in "Howl" and in Broadway's "Next to Normal" -- has joined the cast of Universal and Working Title’s big-screen adaptation of the classic musical.

Because of the intense popularity of the musical, the movie has generated tons of speculation about which actors will join the production. Anne Hathaway, Amanda Seyfried and Eddie Redmayne are confirmed. Sacha Baron Cohen and Helena Bonham Carter, whose names have surfaced in connection with the production, are not officially in at this point.

Tveit, who may be best known from a run on the CW’s Gossip Girl, will play Enjolras, who leads a student rebellion in the streets of Paris and orders Javert's execution.

William Nicholson (Gladiator), Alain Boublil and Claude-Michel Schönberg wrote the screenplay, basing it on the Victor Hugo novel and the musical. The film has a release date of Dec. 7, so Universal needs to move quickly.

Tim Bevan and Eric Fellner of Working Title are producing with Debra Hayward and Cameron Mackintosh.

Tveit, repped by CAA and Elin Flack, will next be seen with Joseph Gordon-Levitt in Premium Rush, which opens in August.